1. Field of the Invention
The present invention relates to a lamp and, more particularly, to a lamp utilizing a fan to trigger air flow for heat-dissipation, and capable of indoor or outdoor illumination.
2. Description of the Related Art
In accordance with FIG. 1, a conventional lamp disclosed in the U.S. Pat. No. 7,575,346 and entitled “LAMP” comprises a housing 81, a heat sink 82, a light emitting element 83 and a cooling fan 84. The housing 81 has a first case 811 and a second case 812, and the first case 811 has an air outlet portion 811a and a transparent portion 811b, and the second case 812 has an air inlet portion 812a. The heat sink 82, the light emitting element 83 and the cooling fan 84 are all disposed inside the housing 81, with the heat sink 82 formed between the light emitting element 83 and the cooling fan 84, and with the light emitting element 83 facing the transparent portion 811b. With this arrangement, when the cooling fan 84 is in operation, air can be inhaled from the air inlet portion 812a, pass through the heat sink 82 and be exhaled from the air outlet portion 811a for dissipating heat generated by the light emitting element 83.
However, the housing 81 of the conventional lamp formed by the first case 811 and the second case 812 not only increases the number of used components but also complicates the whole structure of the conventional lamp. Furthermore, because the heat sink 82, the light emitting element 83 and the cooling fan 84 are all disposed inside the housing 81, it is necessary to piercingly form a plurality of vents for the air inlet and outlet portions 812a and 811a in the housing 81, which leads to the disadvantage of inconvenience in mass production.
Additionally, when the conventional lamp is inserted into a false ceiling that is distant from the ceiling with a sealed compartment defined between these two ceilings, the air inlet portion 812a and the air outlet portion 811a are settled right above the top surface of the false ceiling for artistic considerations, and only the transparent portion 83 remains beneath the false ceiling. However, since the sealed compartment above the false ceiling forms an enclosed space with poor air circulation, it results in poor heat dissipation. As a result, it is difficult to dispel heat and thus service life of the lamp is reduced.
Taiwan Patent No. M346745 entitled “LED LAMP” discloses another conventional lamp as shown in FIG. 2. Referring to FIG. 2, the lamp comprises a housing 91, a heat sink 92, a fan 93 and a LED assembly 94. The housing 91 has an upper case 911 and a lower case 912, and the upper case 911 has a plurality of vents 911a and the lower case 912 has a through-hole 921a. The heat sink 92 is disposed inside the housing 91, with a ventilation channel 95 linking the heat sink 92 and the through-hole 912a of the lower case 912. The fan 93 is also disposed inside the housing 91 and mounts to the heat sink 92. Also, the LED assembly 94 mounts to the heat sink 92 and is exposed to the outside via the through-hole 912a. When the cooling fan 93 is operated, the external air can be inhaled via the vents 911a, pass through the ventilation channel 95 and then be exhaled via the through-holes 912a for dissipating heat energy generated by the LED assembly 94.
However, the housing 91 of the above conventional lamp is also formed by two assembled cases, the upper case 911 and the lower case 912, and suffers the same disadvantages of structural complexity. Meanwhile, even if the ventilation channel 95 is formed between the heat sink 92 and the through-hole 912a, the upper case 911 still has to arrange the plural vents 911a. It is suggested that the conventional structure is still inconvenient in manufacture. Furthermore, although the through-holes 912a are made in contact with the external air when the conventional lamp is inserted into the false ceiling, the improvement in cooling efficiency of the lamp is still limited since the vents 911a are still located in the sealed compartment right above the top surface of the false ceiling. Hence, poor dispelling of heat and air circulation are still concerns in the conventional lamp and it is not enough to efficiently extend the service life of the lamp.